A body side forming a cab side includes an outer panel, an inner panel arranged facing the inner side of the outer panel in the vehicle width direction, and a reinforcement member arranged between the outer panel and the inner panel, wherein these are joined together through welding. Moreover, it is well known that the outer panel is integratedly formed by press forming using a metal plate material such as sheet steel or aluminum alloy sheet (e.g., rolling material).
[Patent Document 1] Japanese Unexamined Patent Application Publication No. 2002-362434